The story
- Latin · borrowed fromquīnquenniālis
- English todayquinquennial
Borrowed from Latin quīnquenniālis, from quīnquennium (“5-year period”) + -ālis, from quīnquennis (“5-year”) + -ium (“-ium: forming abstract nouns”), from quīnque (“five”) + annus (“year”) + -is (suffix forming compound adjectives).
Etymology from Wiktionary, CC BY-SA 4.0.